I'd like to get a detailed report of all your machines (recognized) hardware;
Download, install, and run Everest Home Edition on this machine. (Clean FreeWare) Once it's finished loading and running, click on the Report Wizard in the Menu Bar. Save all hardware related pages (the default) to a TEXT file in a location of your choice. (It will default the location to C:\Program Files\Lavalys\EVEREST Home Edition\Reports, unless you redirect it.)
Compress (zip) the Everest Report text file and attach that zipped text document to your next posting. (When posting, click on Advanced, and just below the posting box you'll see "Additional Options", and within that, "Attach Files". Click on "Manage Attachments" and follow the prompts. Browse to the file and choose UPLOAD.)
Forget about the RAM it's not that, it's a hardware problem. PC world said they will replace all the possible pieces in order of likely-ness after the motherboard.